Republished November 15, 2013, 1:50 p.m. to correct an error in the text.

The latest monthly update of estimated crude oil production in the Bakken region of North Dakota and Montana shows total wellhead output topping 1 million barrels of oil per day (bbl/d) next month. The update appears in the most recent issue of the U.S. Energy Information Administration's Drilling Productivity Report (DPR).

The Bakken region now accounts for a little over 10% of total U.S. oil production and is expected to be the fourth region (along with the Gulf of Mexico, Eagle Ford, and Permian basins) producing more than 1 million bbl/d in the nation in December.

Infrastructure improvements in the central part of the nation carried more of this oil to refineries in recent months, helping to narrow the price difference between the Bakken region and West Texas Intermediate, which is priced at Cushing, Oklahoma.

The growth of crude oil production in the Bakken region is part of a longer-term trend in drilling efficiency gains (see graph below) and has led North Dakota to rank second in crude oil production in the United States, behind only Texas. These production gains have led to increases in gross domestic product in the state as well as increased demand for electricity.